The concept of providing tracked vehicles such as street cars, railway cars, elevated transits have gained great acceptance due to their capability of providing mass transportation systems that can efficiently carry large numbers of people in a relatively rapid fashion. Electric buses of course are not new and were quite successful for a short period of time in several cities in the United States including Chicago. Electric buses were found undesirable after a period of time because of their high maintenance cost resulting from difficulty in delivering electric current to the vehicles from a common source.
For this reason, rapid transit systems have been largely confined to hard wheel vehicles, that is, vehicles whose wheels are made of some metal alloy. Hard wheel vehicles however are totally unsuited, at least as we know them as of the present, of traveling and maneuvering on conventional untracked roadways.
By providing a vehicle that is capable of operating both in an express trackway and also locally in the suburbs and city on conventional roadways, one would eliminate the need for local transportation to and from the rapid transit and also local transportation from and to the rapid transit in the city. There is, however, no system presently available that can practically accomplish this result.
With present vehicle technology, I presume that the vehicle used for this purpose, must be an inflatable tire vehicle. Inflatable tire vehicles, like buses, have generally been driven by petroleum consuming internal combustion engines. These conventional buses would achieve some advantage if they were tracked in terms of speed. The cost of a guiding trackway would be prohibitive however in terms of the speed advantage gained.
Electric vehicles have achieved considerable recognition in the late 1970's due to their minimal use of petroleum products at a time when the world's heavy reliance on dwindeling petroleum reserves appears ominus. Electric vehicles presently developed of the type capable of traveling on conventional roadways are of the battery driven type. The progress of development of these vehicles is severely handicapped due to relatively short discharge time for batteries and the relatively low power level so that vehicles must be very small and travel no more than about one hundred miles without an overnight recharge. This type of vehicle would, for these reasons be totally unsuited for any mass transportation system.